In a coreless rubber crawler, steel cords are embedded in an endless rubber elastic body in the longitudinal direction thereof, and rubber projections used for driving are formed at a constant pitch on an inner peripheral side thereof and rubber lugs are also formed at a pitch on an outer peripheral side thereof. Additionally, the steel cords serve as a center surface of pulling of the rubber crawler, and when the rubber crawler is wrapped around a sprocket or idler, the rubber on the inside repeatedly receives strain of the compression side and the rubber on the outside repeatedly receives strain of the pulling side.
Additionally, when the rubber projections formed on the inner peripheral surface of the rubber crawler are mainly considered, bending deformation is produced between the rubber projections at the time of wraparound because bending rigidity is low between the rubber projections.
On the other hand, when the rubber lugs are mainly considered, bending deformation is produced between the rubber lugs at the time of wraparound because bending rigidity is low between the rubber lugs.
In this case, when the bending deformation portions at the inner peripheral side and the outer peripheral side (ground side) match, those portions experience bending deformation particularly locally, the strain of the rubber of the ground side surface where the rubber is the pulling side becomes larger, and sometimes cracks occur due to cumulative repeated bending use.